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ABSTRACT This study was conducted on a sample of thirty patients selected from Orthodontics department de'Montmorency College of dentistry/ Punjab dental Hospital, Lahore. The purpose of study was to evaluate treatment effects of Distal Jet Appliance during Class-II molar correction with a focus on the magnitude of Maxillary first molar distalization, its tipping, extrusion, rotation as well as anchorage loss at premolar-incisor unit. Pre and post distalization lateral cephalogram and study cast were used as evaluation tools. Results showed that there was 3.88 mm space created during 7.11 months; out of which 2.93 mm (75.52 %) showed molar distalization while 0.93 mm (24.48 %) premolar mesialization as anchorage loss. There was 3.41º molar tipping with 0.20 mm extrusion and second premolar showed 7.33 º distal tipping, 0.90 mm extrusion whereas Incisors showed 1.65 º labial tipping.
Key words: Molar Distalization, Distal Jet, Molar Correction INTRODUCTION The primary goal of orthodontic treatment is at-tainment of an "ideal occlusion", which involves molars placement in class I relationship. Class-II malocclusion usually requires distal movement of maxillary first molars in order to achieve class-I molars and canine relationship.1,2 Many researchers have developed numerous treat-ment modalities for Class-II molar correction from compliance oriented treatment with headgear, Class-II intermaxillry elastics to sliding mechanics, Wilson bimetric distalizing arch system, Molar distalizing bow, Acrylic Cervical Occipital appliance (A.C.C.O) and removable functional appliances to non-compliance treatments using intra-oral devices to distalize the maxillary first molars in to class-I occlusion.3-6 These intraoral devices consist schematically of an anchorage unit (usually comprising premolars or deciduous mo-lars and an acrylic Nance button) and an active unit. Various force-generating devices for molar distalization have been proposed, including repelling magnets, coil springs on continuous archwire, super elastic nickeltitanium arch wires, Jones jig, distal jet, and Keles slider, springs in beta titanium alloy (pendulum, pen-dulum with distal screw, K-loop, intraoral bodily molar distalizer), and vestibular screws combined with pala-tal nickel-titanium coil spring (first class) appliances.7-20 These appliances rely on Nance button for anchor-age reinforcement. Anchorage is considered the most critical factor when correcting Class II- malocclusion not only for initial maxillary molar distalization, but also for subsequent anterior tooth retraction. Anchor-age control is of great importance in orthodontic treat-ment, and researchers have made many modifications to minimize anchorage loss.
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